Project Summary/Abstract The richness of diversity found in our microbial world influences both human health and disease. The latter is evident from immune evasion and the evolution and spread of antibiotic resistance among pathogens, which threatens our ability to effectively treat infectious diseases. Since 1985 the Microbial Population Biology Gordon Research Conference (GRC) has been the premier international meeting on the evolution and ecology of microbial populations. Its long-term objective since 1985 is to improve our understanding of the evolutionary forces that lead to the emergence and maintenance of genetic diversity within and between microbial species. It typically attracts an outstanding and diverse group of scientists who work at the forefront of their discipline. In addition an accompanying Gordon Research Seminar (GRS) for graduate students and postdoctoral fellows precedes the conference since 2013. The specific goal of the 2017 GRC & GRS is to bring together thought leaders from a spectrum of disciplines to present and discuss empirical data and theoretical concepts pertinent to the adaptive evolution of not only microbes, but all other forms of life. The conference and seminar have the following specific aims. Specific Aim 1: Interweave the findings of basic research done to develop and test evolutionary theory with studies done to meet the modern day challenges of emerging infectious diseases, the arms race of antibiotic resistance, sustainable use of natural resources, and global warming. This will be done in nine non-overlapping sessions with the following topics: (i) Evolution and emergence of infectious diseases, (ii) host-microbe coevolution, (iii) evolutionary consequences of epistasis, (iv) the evolution and spread of antibiotic resistance, (v) antibiotic resistance in the field, (vi) genome evolution, (vii) new technologies lead to new opportunities, (viii) ecological interactions of microbial populations, and (ix) the effect of spatial structure on biodiversity. Specific Aim 2: Emphasize novel methods that are needed to better understand the evolution of microbial pathogens and the interactions with each other and their host. Significant advances in technology such as whole genome sequencing have accelerated and deepened our ability to explore the mechanisms of microbial evolution and understand the diversity within microbial populations. One session in particular will focus entirely on novel methods. Specific Aim 3: Highlight the work of younger scientists and enhance the diversity of conference participants. Among the 33 speakers and discussion leaders confirmed so far, 15 are female, 15 are still at the assistant professor level or equivalent, and 20 are from 12 countries other than the US. It is expected that this great diversity in speakers will attract a greater ethnic and geographic diversity among the participants than is typical for this GRC. Moreover, the high representation of young especially female speakers will encourage young woman scientists to continue careers in science. Specific Aim 4: Through a weekend-long GRS for graduate students and postdoctoral fellows, promote scientific interactions among young researchers and offer mentoring and career advice.